The Brazil international sustained the injury in Tuesday’s 2-0 Carling Cup win at Chelsea.
Liverpool confirmed the injury in a statement on Thursday, which read: “Liverpool FC said today a scan had confirmed an injury to the anterior cruciate ligament in Lucas Leiva’s left knee.
“The Brazil international will undergo surgery and unfortunately be ruled out for the remainder of the current campaign.”
Lucas said on Twitter: “Hi all. Just to confirm that I will be out until the rest of season. I am really sad with the news because I was enjoying a lot on the pitch.
“I am sure I will come back stronger and I will achieve everything that I dream with the LFC shirt.
“I am sure I’ll NEVER WALK ALONE.”
